Two-photon imaging has become a useful tool for optical monitoring of neural circuits, but it requires high laser power and serial scanning of each pixel in a sample. This results in slow imaging rates, limiting the measurements of fast signals such as neuronal activity. To improve the speed and signal-to-noise ratio of two-photon imaging, we introduce a simple modification of a two-photon micr...

Digital addressing of the electrical signal in spatial light modulators, as it is the case in present liquid crystal on silicon (LCoS) displays, may lead to temporal phase fluctuations in the optical beam. In diffractive optics applications a reduction in the modulation diffraction efficiency may be expected. Experimental work is done characterizing the fluctuations amplitude and phase depth fo...

Diffractive optical elements (microlenses) for quantum well infrared photodetectors (QWIPs) were fabricated by two techniques: 1) standard lithography of a binary optical structure and 2) PMMA pattern transfer for an analog diffractive optic structure. The binary lenses were fabricated by sequential contact lithography and etching using two binary masks. The analog diffractive lenses were fabri...

Progress in micro-fabrication has enabled not only diffractive optical elements (DOE) but also complex freeform surfaces [1]. Transmissive optical elements can be mainly classified into refractive and diffractive. Ray-tracing techniques are sufficient to explain light propagation through and beyond refractive elements. On the other hand, since interferences are the basis of the diffractive doma...

To the best of our knowledge, the first direct measurement of the dispersive part of the refractive index is performed at extreme-ultraviolet (EUV) wavelengths, where absorption is higher as compared with hard-x-ray and visible wavelengths. A novel diffractive optical element that combines the functions of a grating and a zone plate is fabricated with Fourier optical techniques and employed her...

In this Letter, we introduce a wavefront slope sensor based on a diffractive element. The diffractive element wavefront sensor (DEWS) produces four double overlapping copies of the incoming wavefront acting like a combination of shearing and pyramidal sensors. The DEWS allows a simple and fast slope estimate. The wavefront sampling can be as high as the number of pixel assigned to cover a wavef...

PURPOSE To compare, as a function of pupil size, the through-focus performance and halo features of four diffractive intraocular lenses (IOLs). METHODS Three diffractive bifocal IOLs (ReSTOR +2.5 D SV25T0, Tecnis +2.75 D ZKB00, and AT LISA +3.75 D 809M) and a diffractive trifocal IOL (AT LISA tri +3.33 D, +1.66 D 839MP) were tested in vitro in a modified International Organization for Standar...

Blazed-binary optical elements with only binary ridges or pillars are diffractive components that mimic standard blazed-echelette diffractive elements. We report on the behavior of one-dimensional blazed-binary optical elements with local periods much larger than the wavelength. For this purpose, an approximate model based on both scalar and electromagnetic theory is proposed. The model is test...

In this contribution we present the first diffractive optical elements for soft x-ray differential interference contrast microscopy. Due to an improved calculation method the nanofabrication accuracy of these optics is the same as for comparable normal zone plate optics with the same outermost zone width. Different diffractive optical elements were fabricated with outermost zone width of 100 nm...

We present theory, design, and preliminary experimental studies for a compact wavefront sensor based on lateral shearing interferometry using a binary phase grating, image sensor, and Fourier-based processing. The integrated system places a diffractive element directly onto an image sensor to generate interference fringes within overlapping diffraction orders. The shearing ratio and the interfe...